C(9,6,3) = 7
Method of Construction: dynamic programming covering
Lower Bound: Handbook of Combinatorial Designs section on coverings
1 2 3 4 5 6 1 2 3 4 5 7 1 2 3 4 5 8 1 2 3 4 5 9 1 2 6 7 8 9 3 4 6 7 8 9 1 5 6 7 8 9